Gilly - should I be able to remove the black ring separately or will it unscrew once I press the latches in those two holes (like all the other ones I have worked on)? I have done this on a E320 (and the W123's) but never one of these. I could not see the holes yesterday afternoon when I rode over there to take a look. I guess I did not look close enough. I have to pull a cylinder head from a '89 300SE this morning but may try to get back down there this afternoon to take another look at it. Tumbler issues are the ones I hate the most
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